The removal of selenium from superficial and waste water is a worldwide problem. The maximum limit according to the World Health Organization (WHO) for the selenium in the water is set at a concentration of 10 μg/L. Carbon based adsorbents have attracted much attention and recently demonstrated promising performance in removal of selenium. In this work, several materials (iron oxide based microparticles and graphene oxides materials) and their composites were prepared to remove Se(IV) from water. The graphene oxides were prepared according to the simplified Hummer's method. In addition, the effect of pH, contact time and initial Se(IV) concentration was tested. An electrochemical method such as the differential pulse cathodic stripping voltammetry was used to determine the residual selenium concentration. From the experimental data, Langmuir adsorption model was used to calculate the maximum adsorption capacity. Graphene oxide particles modified by iron oxide based microparticles was the most promising material for the removal of Se(IV) from its aqueous solution at pH 2.0. Its adsorption efficiency reached more than 90% for a solution with given Se(IV) concentration, meanwhile its maximal recorded adsorption capacity was 18.69 mg/g.

• MeSH
• adsorpce MeSH
• časové faktory MeSH
• chemické látky znečišťující vodu izolace a purifikace   MeSH
• elektrochemické techniky metody   MeSH
• elektrody MeSH
• grafit chemie   MeSH
• koncentrace vodíkových iontů MeSH
• mikrosféry MeSH
• roztoky MeSH
• selen izolace a purifikace   MeSH
• statická elektřina MeSH
• teplota MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. METHODS AND RESULTS: A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous soils in Colorado, USA. Based on fatty acid methyl ester analysis and multi-locus sequence analysis (MLSA) using 16S rRNA, gyrB, rpoB and rpoD genes, the isolate was identified as a subspecies of Pseudomonas moraviensis (97.3% nucleotide identity) and named P. moraviensis stanleyae. The isolate exhibited extreme tolerance to SeO3(2-) (up to 120 mmol l(-1)) and SeO4(2-) (>150 mmol l(-1)). Selenium oxyanion removal from growth medium was measured by microchip capillary electrophoresis (detection limit 95 nmol l(-1) for SeO3(2-) and 13 nmol l(-1) for SeO4(2-)). Within 48 h, P. moraviensis stanleyae aerobically reduced SeO3(2-) to red Se(0) from 10 mmol l(-1) to below the detection limit (removal rate 0.27 mmol h(-1) at 30 °C); anaerobic SeO3(2-) removal was slower. No SeO4(2-) removal was observed. Pseudomonas moraviensis stanleyae stimulated the growth of crop species Brassica juncea by 70% with no significant effect on Se accumulation. CONCLUSIONS: Pseudomonas moraviensis stanleyae can tolerate extreme levels of selenate and selenite and can deplete high levels of selenite under aerobic and anaerobic conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Pseudomonas moraviensis subsp. stanleyae may be useful for stimulating plant growth and for the treatment of Se-laden wastewater.

• MeSH
• aerobióza MeSH
• biodegradace MeSH
• Brassicaceae metabolismus   mikrobiologie   MeSH
• endofyty klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• kyselina seleničitá metabolismus   MeSH
• Pseudomonas klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• selen metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Iron-based nanomaterials have high technological impacts on various pro-environmental applications, including wastewater treatment using the co-precipitation method. The purpose of this research was to identify the changes of iron nanomaterial's structure caused by the presence of selenium, a typical water contaminant, which might affect the removal when the iron co-precipitation method is used. Therefore, we have investigated the maturation of co-precipitated nanosized ferric oxyhydroxides under alkaline conditions and their thermal transformation into hematite in the presence of selenite and selenate with high concentrations. Since the association of selenium with precipitates surfaces has been proven to be weak, the mineralogy of the system was affected insignificantly, and the goethite was identified as an only ferric phase in all treatments. However, the morphology and the crystallinity of ferric oxyhydroxides was slightly altered. Selenium affected the structural order of precipitates, especially at the initial phase of co-precipitation. Still, the crystal integrity and homogeneity increased with time almost constantly, regardless of the treatment. The thermal transformation into well crystalized hematite was more pronounced in the presence of selenite, while selenate-treated and selenium-free samples indicated the presence of highly disordered fraction. This highlights that the aftermath of selenium release does not result in destabilization of ferric phases; however, since weak interactions of selenium are dominant at alkaline conditions with goethite's surfaces, it still poses a high risk for the environment. The findings of this study should be applicable in waters affected by mining and metallurgical operations.

• MeSH
• alkálie chemie   MeSH
• chemická precipitace MeSH
• krystalizace MeSH
• kyselina seleničitá chemie   MeSH
• kyselina selenová chemie   MeSH
• minerály chemie   MeSH
• sloučeniny železa chemie   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• spektroskopie Mossbauerova MeSH
• teplota MeSH
• železité sloučeniny chemie   MeSH
• železo chemie   MeSH
• Publikační typ
• časopisecké články MeSH

Cardiotoxicity represents the main drawback of clinical usefulness of anthracycline antineoplastic drugs. In this study, a content of selected elements (Ca, Mg, K, Se, Fe) in the post-mortem removed samples of the myocardial tissue was studied in three groups of rabbits: 1) control group (i.v. saline; n = 10); 2) daunorubicin-receiving animals (DAU; 3 mg/kg, i.v; n = 11); 3) animals receiving cardioprotective iron-chelating agent dexrazoxane (DEX; 60 mg/kg, i.p.; n = 5) prior to DAU. Drugs were administered once weekly for 10 weeks. 5-7 days after the last administration, cardiac left ventricular contractility (dP/dtmax) was significantly decreased in DAU-treated animals (745 +/- 69 versus 1245 +/- 86 kPa/s in the control group; P < 0.05), while in the DEX + DAU group it was insignificantly increased (1411 +/- 77 kPa/s). Of the myocardial elements' content studied, a significant increase in total Ca against control (16.2 +/- 2.4 versus 10.6 +/- 0.9 microg/g of dry tissue; P < 0.05) was determined in the DAU-group, which was accompanied with significant decreases in Mg and K. In the heart tissue of DEX-pretreated animals, no significant changes of elements' content were found as compared to controls, while the Ca content was in these animals significantly lower than in the DAU group (9.1 +/- 0.4 versus 16.2 +/- 2.4 microg/g; P < 0.05). Hence, in this study we show that systolic heart failure induced by chronic DAU administration is primarily accompanied by persistent calcium overload of cardiac tissue and the protective action of DEX is associated with the restoration of normal myocardial Ca content.

• MeSH
• antibiotika antitumorózní toxicita   MeSH
• antracykliny toxicita   MeSH
• draslík metabolismus   MeSH
• financování organizované MeSH
• hořčík metabolismus   MeSH
• kardiomyopatie chemicky indukované   metabolismus   MeSH
• králíci MeSH
• modely nemocí na zvířatech MeSH
• myokard metabolismus   MeSH
• razoxan toxicita   MeSH
• selen metabolismus   MeSH
• stopové prvky metabolismus   MeSH
• vápník metabolismus   MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• zvířata MeSH

Nfs-like proteins have cysteine desulfurase (CysD) activity, which removes sulfur (S) from cysteine, and provides S for iron-sulfur cluster assembly and the thiolation of tRNAs. These proteins also have selenocysteine lyase activity in vitro, and cleave selenocysteine into alanine and elemental selenium (Se). It was shown previously that the Nfs-like protein called Nfs from the parasitic protist Trypanosoma brucei is a genuine CysD. A second Nfs-like protein is encoded in the nuclear genome of T. brucei. We called this protein selenocysteine lyase (SCL) because phylogenetic analysis reveals that it is monophyletic with known eukaryotic selenocysteine lyases. The Nfs protein is located in the mitochondrion, whereas the SCL protein seems to be present in the nucleus and cytoplasm. Unexpectedly, downregulation of either Nfs or SCL protein leads to a dramatic decrease in both CysD and selenocysteine lyase activities concurrently in the mitochondrion and the cytosolic fractions. Because loss of Nfs causes a growth phenotype but loss of SCL does not, we propose that Nfs can fully complement SCL, whereas SCL can only partially replace Nfs under our growth conditions.

• MeSH
• cytosol enzymologie   MeSH
• fylogeneze MeSH
• kompartmentace buňky MeSH
• lyasy štěpící vazby C-S genetika   metabolismus   MeSH
• lyasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• messenger RNA genetika   metabolismus   MeSH
• mitochondrie enzymologie   MeSH
• protozoální geny MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• RNA interference MeSH
• RNA protozoální genetika   metabolismus   MeSH
• Trypanosoma brucei brucei enzymologie   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: The aim of the study was to evaluate the degree of ischemia reperfusion syndrome (IRS) in serious ischemic insult of a kidney transplant and to try to mitigate the production of reactive oxygen substances (ROS) and inflammatory response. METHODS: The study was performed on 14 white pigs (20 kg). The pigs were divided in couples using a negative cross-matching and the couples were divided into the two groups. Each animal from the compatible couple was a donor/recipient of a kidney to/from the counterpart. Group II (TxII) received the intravenous antioxidants. Group I (TxI) was a control group. L-ascorbic acid 125 mg, selenium 4.4 mg, tocoferol 50 mg and N-acetyl-cysteine 200 mg were used as the antioxidants. They were applied intravenously to the TxII animals for 20 minutes before reperfusion of a kidney transplant. A serious ischemic insult was created by the left kidney hilum's cross-clamping for 30 min before donation. After the kidneys' removal, the left ones were flushed with Histidine Tryptophan Ketoglutarate (HTK) preservation solution and transplanted after the 1.5 hour (in the meantime stored in melted ice). Venous blood samples were taken for the assessment of malondialdehyde (MDA), reduced glutathione (GSH), glutathioneperoxidase (GSHPx), antioxidative capacity of plasma (AOC), interleukin 6 (IL-6), and tumor-necrosis factor alfa (TNFalfa) prior to the nefrectomy, before application of ROS scavengers (TxII), and during the 120-minute period after the transplantation (TxL+TxII). RESULTS: There wasn't a significant difference neither in production of MDA, nor in the levels of GSH, GSHPx, AOC, IL6 and TNFalfa between the TxI and TxII groups. CONCLUSIONS: Based on our results, we cannot conclude that the intravenous application of ROS scavengers in given combination and amount, administered to the recipient in the period just before transplantation, is a useful protective mechanism against kidney damage during IRS (Fig. 3, Ref. 17). Full Text (Free, PDF) www.bmj.sk.

• MeSH
• antioxidancia aplikace a dávkování   farmakologie   MeSH
• financování organizované MeSH
• intravenózní infuze MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• reperfuzní poškození metabolismus   prevence a kontrola   MeSH
• scavengery volných radikálů aplikace a dávkování   farmakologie   MeSH
• Sus scrofa MeSH
• transplantace ledvin MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

Mathematical modelling of the relationships between mineral inputs and outputs would enable the prediction of mineral requirements of poultry under a wide range of conditions. To establish the feasibility of possible modelling of mineral requirements, the current study aimed to describe the individual mineral concentrations of whole bodies of quail over the life cycle from hatching to 70 days of age. Quail were reared indoors without any restrictions that could limit growth. Sampling of birds (n = 6-18) was carried out at 0, 3, 7, 14, 21, 35, 49 and 70 days after hatching. Freeze-dried samples of whole bodies (digestive contents removed) were analysed for ash, and macrominerals (calcium, magnesium, phosphorus, potassium, sodium) and microminerals (copper, iron, manganese, nickel, selenium, zinc). Ash concentration followed a curvilinear trend, with a maximum of 101.7 g/kg dry matter at 32.77 days. Individual mineral concentrations, expressed as a proportion of ash, were fluctuating over time, with the most prominent changes at 3 days and again at either 14 or 21 days. Dissimilar patterns in individual mineral concentrations resulted that ratios between minerals followed inconsistent patterns over time. Although mineral contents in absolute quantities can be described through modelling over the entire life cycle of the bird, it can be concluded that variable concentrations of individual minerals could complicate further model development.

• MeSH
• biologické modely MeSH
• Coturnix fyziologie   MeSH
• minerály chemie   MeSH
• složení těla fyziologie   MeSH
• stárnutí fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Výskyt malignit u dlouhodobě dialyzovaných nemocných je vyšší než u jiných osob. Problematika malignit a dialyzačního léčení je zde zpracována z několika hledisek: A. Malignity mohou způsobit selhání ledvin (nádory močového ústrojí, von Hippel-Lindauova chorobu, Wilmsův nádor, mnohočetný myelom, nádory s útlakem močových cest). B. Léčení malignit může vyústit do renálního selhání (nefrektomie, akutní rozpad nádorových buněk při chemoterapii, postiradiační fibróza, přímé toxické postižení). C. Dialyzovaní nemocní mají zvýšené riziko vzniku zhoubného onemocnění, zejména močového ústrojí, ale též faryngu a laryngu, štítné žlázy a dalších. Roli hrají: základní příčina ledvinného selhání (analgetická a Balkánská nefropatie, nefropatie z čínských bylin aj.), změněné metabolické prostředí s retencí potenciálních karcinogenů, nedostatek selenu a jiných látek, získané cysty ledvin, porušená imunita, pokles diurézy (snížený „wash-effect“) a snad vliv vlastní dialýzy (ftaláty, etylenoxid, nitrosaminy aj.) atd. D. Zvláštnosti diagnostiky malignit u nemocných v dialyzačním léčení. Je zmíněn sporný význam tzv. nádorových markerů. Aktivní pátrání po malignitách se má soustředit na močový systém, u ostatních je třeba zvážit individuální rizikový profil nemocných. E. Metod náhrady funkce ledvin lze využít při léčení nádorových chorob – léčení syndromu rozpadu nádorových buněk a hyperkalcémie dialýzou, odstraňování paraproteinů u myelomu plazmaferézou, využití postupů peritoneální dialýzy v aplikaci chemoterapie. F. Maligní onemocnění – dialyzační léčení – etické problémy. Ukončení dialyzačního léčení u progredujících malignit spojených s utrpením by mělo vycházet ze souhlasu informovaného nemocného, se zajištěním maximální paliativní terapie včetně eventuální paliativní ultrafiltrace při sklonu k plicnímu edému.

Incidence of malignancies in patients on dialysis is higher than in the comparable population. The topic is discussed from different points of view: A. Malignancy as a cause of renal failure (renal and urinary tract tumors, von Hippel- Lindau disease, Wilms tumor, multiple myeloma, tumors that compress urinary tract). B. Treatment of malignancies may result in renal failure and dialysis (nephrectomy, tumor-lysis syndrome, postradiation fibrosis, direct toxic effect of chemotherapy). C. Dialyzed patients are in higher risk of malignancies, especially those of the kidney and urinary tract but also of pharynx and larynx, thyroid gland etc. The following factors may play some roles: the basic disease, (e.g. analgesic and Balcan nephropathies, China Herba nephropathy etc.), changed metabolic milieu with retention of carcinogens, deficiency of selenium and other substances, acquired renal cysts, compromised immunity, decreased “wash-effect“ in oligo-anuria and possible influence of dialysis itself (contact with phtalates, ethylenoxide, nitrosamines etc.). D. Special problems in diagnostics of malignancies. Controversial validity of s.c. „tumor markers“ is mentioned. Among the causes of death in dialyzed patients cardiovascular and infectious diseases predominate. The active search for renal and urinary tract tumors should be performed. All other diagnostic procedures depend on the individual patient’s risk profile. E. Methods of renal substitution are used in the treatment of malignancies (e.g. dialysis in the tumor-lysis syndrome, plasma filtration to remove paraproteins, intraperitoneal administration of chemotherapy similar to peritoneal dialysis approach). F. Malignant tumors and dialysis – some ethical problems. Withdrawal of dialysis in severely suffering patients should be approved by an informed patient and followed by maximal palliative therapy including palliative ultrafiltration if threat of lung edema occurs.

• MeSH
• dialýza etika   metody   škodlivé účinky   MeSH
• finanční podpora výzkumu jako téma MeSH
• informovaný souhlas pacienta MeSH
• nádorové biomarkery krev   MeSH
• nádory diagnóza   etiologie   terapie   MeSH
• peritoneální dialýza etika   metody   MeSH
• prostatický specifický antigen krev   MeSH
• renální insuficience etiologie   terapie   MeSH
• Publikační typ
• přehledy MeSH

BACKGROUND: Acquired calcified aortic valve stenosis is the most common valve disease in adulthood. In the etiopathogenesis of this complex pathology, the importance of inflammation is mentioned, in which non-infectious influences represented by the biological effects of metal pollutants may participate. The main goal of the study was to determine the concentration of 21 metals and trace elements-aluminium (Al), barium (Ba), cadmium (Cd), calcium (Ca), chrome (Cr), cobalt (Co), copper (Cu), gold (Au), lead (Pb), magnesium (Mg), mercury (Hg), molybdenum (Mo), nickel (Ni), phosphorus (P), selenium (Se), strontium (Sr), sulfur (S), tin (Sn), titanium (Ti), vanadium (V) and zinc (Zn)-in the tissue of calcified aortic valves and to compare them with the concentrations of the same elements in the tissue of healthy aortic valves in the control group. MATERIAL AND METHODS: The study group consisted of 49 patients (25 men, mean age: 74) with acquired, severe, calcified aortic valve stenosis with indicated heart surgery. The control group included 34 deceased (20 men, median age: 53) with no evidence of heart disease. Calcified valves were explanted during cardiac surgery and deep frozen. Similarly, the valves of the control group were removed. All valves were lyophilized and analyzed by inductively coupled plasma mass spectrometry. The concentrations of selected elements were compared by means of standard statistical methods. RESULTS: Calcified aortic valves contained significantly higher (p < 0.05) concentrations of Ba, Ca, Co, Cr, Mg, P, Pb, Se, Sn, Sr and Zn and-in contrast-lower concentrations of Cd, Cu, Mo, S and V than valves of the control group. Significant positive correlations of concentrations between the pairs Ca-P, Cu-S and Se-S and strong negative correlations between the elements Mg-Se, P-S and Ca-S were found in the affected valves. CONCLUSION: Aortic valve calcification is associated with increased tissue accumulation of the majority of the analyzed elements, including metal pollutants. Some exposure factors may increase their accumulation in the valve tissue. A relationship between exposure to environmental burden and the aortic valve calcification process cannot be ruled out. Advances in histochemical and imaging techniques allowing imaging of metal pollutants directly in valve tissue may represent an important future perspective.

• Publikační typ
• časopisecké články MeSH